DeFi (Decentralised Finance) is a hot topic these days. "How to DeFi" is prepared by Coingecko team. It is available for sale, but also you can get it with Coingecko's candies. I saw this book months ago, but only recently go it, as I had enough candies in my account. I thought that even though I know something about DeFi, there might be some useful information.
And that's actually a good book, especially for those who do not know much about DeFi or cryptocurrencies in general. Some of my friends told me that they didn't get what DeFi ("you need to stake some shitcoins over another shitcoins and then you are liquidity provider" as one of them described his experience). But this book clarified for them what DeFi is and why it is needed.
The book starts with an introduction and explanation of traditional financial system disadvantages and how DeFi can help to overcome them. It explains basic aspects such as how Ethereum works, wallets, stablecoins.
Then there is a chapter about Lending and Borrowing, which explains Compound and gives a guide to lend and borrow. All other chapters have also particular guides with images that might be useful for the new users.
Uniswap and dYdX are shown are examples of DEX (Decentralised Exchanges), TokenSets - as example of Decentralised Fund Management, PoolTogether - lottery, Sablier - decentralized payments, Nexus Mutual and Opyn - as examples of insurance.
There are also chapters about DeFi in action and thoughts about the future. I especially liked the example of how DeFi helps to fight high inflation in Argentina.
In conclusion, that's a good book and probably something I can recommend for people asking "What is DeFi". The book is not big, it's possible to read it less than in a day and it gives the basic answer. It won't teach you how to make huge profits in DeFi, but it can help clarify to you this area and teach you how to use basic projects.